36" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 18" Round Duct Pipe + Product Details Size -

+ Product Details Size - 24"w X 8"h is the size for the duct opening measurement only

+ Product Details Size - 16"w X 14"h is the size for the duct opening measurement only

875" height

+ Product Details Perfect Fit & Easy Sizing - Designed for a 20" x 34" OR 34" x 20" duct opening (measured at the opening)

36" x 24" Cube Core Eggcrate Return Air Filter Grille for 1" Filter 18" Round Duct Pipe + Product Details Size -+ Product Details Perfect Fit & Easy Sizing Designed for a 36" x 24" OR 24" x 36" duct opening (measured at the opening), with actual outer dimensions of 38. 5" W x 26. 5" H. Please check the measuring guide to ensure a proper fit. Filter Size 35. 75" x 23. 75" x 1" Premium Airflow Efficiency High performance cube core eggcrate design allows 95% airflow efficiency, reducing energy costs and maximizing HVAC system lifespan. Durable, Rust Free Aluminum